The State of Python… and the web

Armin Ronacher // @mitsuhiko

Who am I

• Armin Ronacher (@mitsuhiko)

• Founding Member of the “Pocoo Team”

• we're doing Jinja2, Werkzeug, Flask, Pygments, Sphinx and a bunch of other stuff.

Crossroads

Python 3• The Elephant in the Room

Python in 2011

• The big Python 3 versus Python 2 debate

• PyPy is making tremendous progress

Recent Python News

• Unladen Swallow is resting

• Python 3.2 was released

• Python's packaging infrastructure is being worked on.

• distutils2 / packaging in Python 3

Recent PyPy News

• PyPy gets experimental support for the CPython C API

• PyPy got 10.000$ by the PSF

• PyPy 1.5 released

• Are you using PyPy in production? Why not? http://bit.ly/pypy-survey

PyPy

PyPy Right Now

• “Python written in Python”

• PyPy trunk 3.7x faster than CPython over a wide variety of benchmarks

• Up to 40x faster for certain benchmarks

• Compatible with Python 2.7.1

Really Fast

• http://speed.pypy.org/

Things that will break

• There is only experimental support for the Python C API and it will always be slow.

• Different garbage collection behavior, no reference counting.

Things that work• Django

• Flask

• ctypes

• pyglet

• twisted

• sqlite

The Bonus

• Sandbox support

• Stackless execution mode

• A .NET backend

Python 3

Python 3 is …

• … where all new language developments are happening

• … adding unicode to the whole stack

• … cleaning up the language

• … breaking backwards compatibility

The Good Parts

• Introduces unicode into exceptions and source compilation as well as identifiers

• Greatly improved IO API regarding unicode

• New language constructs

• Implementation cleaned up a lot

New Constructs

• Extended iterable unpacking

• Keyword only arguments

• nonlocal

• Function parameter and return value annotations

Improved Things

• print as a function

• Improved syntax for catching and raising exceptions

• Ellipsis (…) syntax element now available everywhere

Different Behavior

• More powerful metaclasses (but removed support for some tricks people relied on*)

• List comprehensions are now from the behavior much closer to generator expressions

• * don't abuse undocumented “features”

Warts removed• Argument unpacking

• Unused nested tuple raising syntax

• Longs no longer exposed

• Classic classes gone

• Absolute imports by default

• Obscure standard library modules

Common Ground

New in 2.6/2.7

• Explicit byte literals, make upgrading easier

• Advanced string formatting

• Print as a function

• Class decorators

• New IO library

New in 2.6/2.7

• The multiprocessing package

• Type hierarchy for numbers

• Abstract base classes

• Support for fractions

Going Forward

Beauty or Speed

• Right now it's a decision between the beauty of the code (Python 3) or the raw performance (PyPy).

• PyPy itself will probably always be written in Python 2, but the interpreter might at one point support Python 3.

Library Support

• Numeric libraries work great on Python 3 and benefit of improvements in the language.

• PyPy still lacks proper support for the C-API of Python.

Predictions

• Most people will write their code against 2.7 with the intention of supporting PyPy.

• Libraries that require the Python C API will become less common

• We will see libraries that support targeting both Python 2.7 and Python 3.x.

Python and the Web

WSGI

• New revision for Python 3

• There is some work done to port implementations to Python 3

• No longer something people actively care about. “It works”

New Developments

• Improvements to PyPy's support for database adapters

• Improvements in template compilation to take advantage of PyPy's behavior.

• Porting some libraries over to Python 3.

Making Python 3 work

Python 3 can work

• Start porting libraries over.

• Issues with Python 3 will only be resolved if people actively try to port.

• The higher level the application, the easier to port. Libraries are the culprit.

And it's not hard

• When you're at the port where you can drop Python 2.6 support, you can write code that survives 2to3 mostly without hacks in the code.

• http://bit.ly/python3-now

Frameworks

We're doing great

• WSGI works out well in practice.

• Pylons and BFG -> Pyramid, nice introduction into the ZOPE world.

• Less and less framework specific code out there, easier to reuse.

Less Frameworks*

• Django

• Pyramid

• Flask

• Bottle

• web.py

Low Level

• Werkzeug

• WebOb

• these two might actually merge at one point in the future

Frameworks are Good

• New frameworks are necessary to explore new paradigms and concepts.

• It's surprisingly easy to switch frameworks or parts of frameworks in Python.

• Frameworks are merging and evolving.

Thank you

Contact / Slides

• Armin Ronacher

• @mitsuhiko

• http://lucumr.pocoo.org/

• http://lucumr.pocoo.org/talks/ <- Slides